text: Bulbous bows embody the following defining characteristics:
  * Length-wise shape
  * Cross-section
  * Length of forward projection 
  * Position of the shape's axis (e.g. forward or upwards)
  While the primary purpose of such bulbs is to reduce the power required to drive a vessel at its operating speed, their sea-keeping characteristics are also important. A ship's wave-making characteristics at its operating speed are reflected in its Froude number. A ship designer can compare the length at the water line for a design with and without a bulb necessary to power the vessel at its operating speed. The higher the speed, the bigger the benefit of the bulbous bow in diminishing the necessity for a longer water line to achieve the same power requirement. Bulbs typically are v-shaped on the bottom to minimise slamming in rough seas.